The long-range objective of these studies is to elaborate the role of thiol-disulfide reactions in biological control processes. The initial studies have shown that elevated levels of oxidized glutathione (GSSG) and protein-glutathione disulfde (PSSG) occur in the quiescent or dormant states of representative members of the plant (wheat and barley embryos), fungal (Neurospora crassa conidia, dry yeast) and animal (Artemia salina eggs) kingdoms, and that these levels decline upon activation. A substantial body of evidence implicates a role for GSSG in the control of protein synthesis. Further studies of these systems will (1) test the role of GSSG in controlling protein synthesis through in vitro studies with the wheat embryo system and (2) test the role of PSSG bonds. Since glutathione had been thought to be a universal component of cells, we were surprised to find in studies of bacteria that strict anaerobes and most gram-positive bacteria, including all studied spore-formers, lack glutathione whereas gram-negative aerobes and facultative anaerobes have it. This finding underscores the importance of two objectives for further study: (1) to determine the nature of those thiols present in gram-positive bacteria and to ascertain whether thiol-disulfide reactions of these are involved in sporulation or germination; (2) to ascertain if glutathione is a universal component of eucaryotes, with emphasis on protista, and what other thiols are present. To accomplish this a proposed scheme for general, sensitive, and specific analysis of thiols and of disulfide regulation in eucaryotic dormancy; (2) providing greatly improved methodology for analysis of thiols and disulfides; (3) establishing the nature and distribution of thiols in biological systems; (4) testing the role of thiol-disulfide control in spore-forming bacteria.